Mirror device

ABSTRACT

A mirror device has a light-transmissive substrate and at least one organic EL element supported on the back surface of the light-transmissive substrate, and emits light from the front surface of the light-transmissive substrate. The organic EL element has an organic layer containing a light-emitting layer layered between a light-transmissive electrode and a reflection electrode that are opposite to each other. The light-transmissive electrode is formed on the light-transmissive substrate. The mirror device has a plurality of metal mirror surface portions that each have an area smaller than the area of the light-transmissive electrode and are distributed and disposed on the front surface of the light-transmissive substrate so as to be opposite to the light-emitting layer.

TECHNICAL FIELD

The present invention relates to a mirror device that has alight-emitting function and contains an organic electroluminescentelement.

BACKGROUND ART

An organic electroluminescent element is a light-emitting element thatis configured by layering an anode, an organic layer containing alight-emitting layer, and a cathode in this order on a transparent glasssubstrate, and expresses electroluminescence (hereinafter referred to asEL) by injection of current in the organic layer through the anode andthe cathode. The organic EL element is a self-emitting surface emissiondevice, and is used for a display device and an illuminator.

As a mirror device, a mirror equipped with an EL illuminator in which anorganic EL element is disposed around the mirror in a frame shape and anobject such as the face and the like of a user can be reflected has beenproposed (see Patent Literature 1).

A sun visor assembly for automotive vehicles with an illuminatedrear-view mirror has also been proposed (see Patent Literature 2).

CITATION LIST Patent Literature

Patent Literature 1: Japanese Patent Application Laid-Open No.2003-217868

Patent Literature 2: Japanese Patent No. 2625177

SUMMARY OF INVENTION Technical Problem

In the mirror equipped with an EL illuminator of Patent Literature 1,since a light source such as the organic EL element is disposed on aframe around the mirror, the area of the mirror decreases. The mirrorhas a defect in which light cannot be accurately applied to a portion ofthe face that the user wants to see.

In the sun visor assembly of Patent Literature 2, an illuminationportion such as a lamp is directly provided in front of both sides of amirror surface. Therefore, the sun visor assembly has a problem in whichit is difficult to emit light uniformly.

In the mirror device, a light-emitting portion is added and disposedsimply in front of and behind the mirror. Therefore, the mirror devicehas a defect in which the thickness of the whole mirror deviceincreases.

As an example, an object of the present invention is to provide a mirrordevice that has a light-reflecting function and suppresses an increasein the thickness of the device to emit light in a forward direction.

Solution to Problem

A mirror device of the present invention is a mirror device that has alight-transmissive substrate and at least one organic EL elementsupported on the back surface of the light-transmissive substrate, andemits light from the front surface of the light-transmissive substrate,wherein the organic EL element has an organic layer containing alight-emitting layer layered between a light-transmissive electrode anda reflection electrode that are opposite to each other, thelight-transmissive electrode is formed on the light-transmissivesubstrate, and the mirror device has a plurality of metal mirror surfaceportions that each have an area smaller than the area of thelight-transmissive electrode and are distributed and disposed on thefront surface of the light-transmissive substrate so as to be oppositeto the light-emitting layer.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a front view of a part of a mirror device of an organic ELpanel according to a first embodiment of the present invention which iscut out, and a partially enlarged front view thereof.

FIG. 2 is a cross-sectional view taken along line C-C in FIG. 1.

FIG. 3 is an enlarged cross-sectional view of a part of the mirrordevice of the organic EL panel according to the first embodiment.

FIG. 4 is a schematic cross-sectional view of a part of the organic ELpanel which shows an operation of the mirror device of the organic ELpanel shown in FIG. 1.

FIG. 5 is a schematic cross-sectional view of a part of a mirror deviceof an organic EL panel according to a modified example of the firstembodiment.

FIG. 6 is a front view of a part of a mirror device of an organic ELpanel according to another modified example of the first embodimentwhich is cut out, and a partially enlarged front view thereof.

FIG. 7 is a partially enlarged front view of a part of a mirror deviceof an organic EL panel according to another modified example of thefirst embodiment.

FIG. 8 is a partially enlarged front view of a part of a mirror deviceof an organic EL panel according to further another modified example ofthe first embodiment.

FIG. 9 is a partially enlarged front view of a part of a mirror deviceof an organic EL panel according to yet another modified example of thefirst embodiment.

FIG. 10 is a partially enlarged front view of a part of a mirror deviceof an organic EL panel according to another modified example of thefirst embodiment.

FIG. 11 is a schematic cross-sectional view of a part of a mirror deviceof an organic EL panel according to a second embodiment of the presentinvention.

FIG. 12 is a schematic cross-sectional view of a part of a mirror deviceof an organic EL panel according to a third embodiment of the presentinvention.

FIG. 13 is a schematic cross-sectional view of a part of a mirror deviceof an organic EL panel according to a fourth embodiment of the presentinvention.

FIG. 14 is a schematic cross-sectional view of a part of a mirror deviceof an organic EL panel according to a fifth embodiment of the presentinvention.

FIG. 15 is a schematic cross-sectional view of a part of a mirror deviceof an organic EL panel according to a sixth embodiment of the presentinvention.

FIG. 16 is a schematic cross-sectional view of a part of a mirror deviceof an organic EL panel according to a seventh embodiment of the presentinvention, and a partial cross-sectional view thereof.

DESCRIPTION OF EMBODIMENTS

Hereinafter, embodiments of the present invention will be described withreference to the drawings.

First Embodiment

FIG. 1 shows a configuration of a mirror device that is an organic ELpanel OELD according to a first embodiment of the present invention.

The organic EL panel OELD includes a plurality of organic EL elementsOELs that are divided by banks BKs on a light-transmissive plate made ofa glass or a resin as a substrate 1. For example, the banks BKs are madeof a dielectric material such as an optical glass and an optical resin.The organic EL elements OELs are each a strip-shaped light-emittingportion that extends in a y direction of a xy main plane of thesubstrate 1. The organic EL elements OELs are groups of organic ELelements R, G, and B that emit light of different luminescent colorssuch as red R, green G, and blue B, respectively, from a front surface 1a of the light-transmissive substrate 1. The organic EL elements R, G,and B are aligned in parallel on the substrate 1. Each of sets of theorganic EL elements OELs having RGB luminescent color that emits lightwith each of luminescent colors of red, green, and blue is aligned in anx direction.

The organic EL panel OELD has the banks, the organic EL elements, and aplurality of metal mirror surface portions MIRs that are distributed anddisposed on the front surface 1 a of the substrate 1. The metal mirrorsurface portions MIRs are configured in stripes so that the metal mirrorsurface portions MIRs as strip-shaped light-reflecting portionsextending in the y direction and spaces SPs are alternately disposed inthe x direction, as shown in FIG. 1. In an enlarged part of the metalmirror surface portions MIRs aligned in a matrix that is shown by awhite arrow in FIG. 1, the metal mirror surface portions are shown withhatching.

When the metal mirror surface positions MIRs each are viewed from aboveas shown in FIG. 1, in the embodiment, the metal mirror surface portionsMIRs each have such a width that covers each of the banks BKs, and themetal mirror surface portions MIRs with the same width are equallydisposed on the light-emitting portions. Each of the metal mirrorsurface portions MIRs has an area smaller than the area of each of thelight-emitting portions of the organic EL elements OELs. During drivingof the elements, light of the organic EL elements OELs can be extractedfrom the spaces SPs between the metal mirror surface portions MIRs asshown in FIG. 1.

Thus, the metal mirror surface portions MIRs each have the same shapeand the same area, and are disposed in uniform distribution.Alternatively, the shapes and the areas of the metal mirror surfaceportions MIRs may be different, or not the same, as long as the areasare smaller than the areas of the light-emitting portions. Herein, themetal mirror surface portions MIRs and the spaces SPs are eachconfigured at uniform intervals. For example, when the widths of eachside of the metal mirror surface portions MIRs are 0.05 mm or less,which cannot be distinguished with the naked eye, and distances betweenthe metal mirror surface portions MIRs and the organic EL elements OELsare as short as 0.05 mm or less, light is leaked from the spaces SPsduring driving, and the organic EL panel can be utilized as a mirrorthat emits light through the whole surface. In addition, the organic ELpanel can function as one mirror during non-driving of the elements.When the brightnesses of the organic EL elements are adjusted each orfor each group of colors, light that is recognized as a singleluminescent color by mixing red, green, and blue lights at any ratio isemitted from the front surface of the substrate 1 as a light extractionsurface. All the organic EL elements OELs are connected to anelement-driving portion, which is not shown in the drawing.

As shown in FIG. 2, each of the organic EL elements OELs is configuredby layering a light-transmissive electrode 2, an organic layer 3containing a light-emitting layer, and a reflection electrode 4 on aback surface 1 b of the substrate 1 between the banks BKs. Thestrip-shaped light-transmissive electrode 2 is aligned for each of theorganic EL elements OELs so as to extend in parallel to the y directionbetween the banks BKs on the substrate 1. The light-transmissiveelectrode 2 of each of the organic EL elements OELs is connected to theelement-driving portion, which is not shown in the drawing. For example,a substrate 1 in which metal mirror surface portions MIRs andlight-transmissive electrodes 2 are each formed at predeterminedpositions on the front surface and the back surface in a pattern isprepared, and banks BKs having a forward-tapered structure are formedfrom a light-transmissive dielectric material in the y direction betweensides of the adjacent light-transmissive electrodes 2 byphotolithography or the like. A predetermined organic layer 3 is formedon the light-transmissive electrodes 2 between the banks BKs by aninkjet method or the like. Subsequently, a film is formed from areflection electrode material on the organic layer 3 between the banksBKs and the top surfaces of the banks BKs by a vapor deposition methodor the like.

Since the banks BKs have a so-called forward-tapered structure, in whichsides of the banks spread toward the light-transmissive electrode 2, thereflection electrode 4 becomes a common electrode having the sameelectric potential over the organic EL elements OELs. The mirror deviceof the embodiment functions as a so-called bottom emission type organicEL panel in which light generated in the organic layer 3 by applying avoltage to the light-transmissive electrodes 2 and the reflectionelectrode 4 is extracted from the front surface 1 a of the substrate 1.

As shown in FIG. 3, when the light-transmissive electrode 2 is an anodeand the reflection electrode 4 is a cathode, the organic layer 3 of eachof the organic EL elements OELs is typically configured by layering ahole injection layer 3 a, a hole transport layer 3 b, a light-emittinglayer 3 c, an electron transport layer 3 d, and an electron injectionlayer 3 e in this order. Further, in the layered structure of theorganic layer 3, the components except for the substrate may be layeredin reverse order. The organic layer 3 is not limited to this layeredstructure, and for example, may have a layered structure that includesat least a light-emitting layer by adding a hole blocking layer (notshown) between the light-emitting layer 3 c and the electron transportlayer 3 d, or includes a charge transport layer usable as another layer.The organic layer 3 may be configured so that the layered structure doesnot include a hole transport layer 3 b, a hole injection layer 3 a, or ahole injection layer 3 a and an electron transport layer 3 d.

[Light-Transmissive Electrode]

The light-transmissive electrode 2 as an anode may be made ofindium-tin-oxide (ITO), ZnO, ZnO—Al₂O₃ (i.e., AZO), In₂O₃—ZnO (i.e.,IZO), SnO₂—Sb₂O₃ (i.e., ATO), or RuO₂. It is preferable that a materialhaving a transmittance of at least 10% or more in the wavelength oflight emitted from the light-emitting layer be selected for thelight-transmissive electrode 2. The light-transmissive electrode 2usually has a single-layer structure, but may have a layered structureincluding a metal thin film. For example, as a material for the metalthin film, an appropriate metal such as tin, magnesium, indium, calcium,aluminum, and silver, or an alloy thereof is used. Specific examplesthereof may include a magnesium-silver alloy, a magnesium-indium alloy,and an aluminum-lithium alloy. A silver thin film with a thickness of 20nm as the metal thin film has a transmittance of 50%. An Al film with athickness of 10 nm as the metal thin film has a transmittance of 50%. Amagnesium-silver alloy film with a thickness of 20 nm as the metal thinfilm has a transmittance of 50%. The configuration of the metal thinfilm depends on a material, a film forming method, and a condition.However, when the lower limit of the film thickness is 5 nm,conductivity can be secured.

[Hole Injection Layer]

It is preferable that the hole injection layer 3 a be a layer containingan electron-accepting compound (i.e., hole-transporting compound).

From the viewpoint of charge injection barrier from the anode into thehole injection layer, it is preferable that the hole-transportingcompound be a compound having an ionization potential of 4.5 eV to 6.0eV. Examples of the hole-transporting compound may include an aromaticamine derivative, a phthalocyanine derivative typified by copperphthalocyanine (so-called CuPc), a porphyrin derivative, anoligothiophene derivative, a polythiophene derivative, a benzyl phenylderivative, a compound having a tertiary amine connected through afluorene group, a hydrazone derivative, a silazane derivative, asilanamine derivative, a phosphamine derivative, a quinacridonederivative, a polyaniline derivative, a polypyrrole derivative, apolyphenylenevinylene derivative, a polythienylenevinylene derivative, apolyquinoline derivative, a polyquinoxaline derivative, and carbon. Thederivative used herein includes, for example, in the case of an aromaticamine derivative, an aromatic amine itself and a compound having anaromatic amine as a main skeleton, and the derivative may be a polymeror a monomer.

As the hole-transporting compound, a conductive polymer (so-calledPEDOT/PSS) obtained by polymerizing 3,4-ethylenedioxythiophene as apolythiophene derivative in a high-molecular-weight polystyrenesulfonicacid is also preferred. Further, the terminal of the polymer ofPEDOT/PSS may be capped with methacrylate or the like.

[Hole Transport Layer]

As a material for the hole transport layer 3 b, a materialconventionally used as a constituent material for a hole transport layermay be used. Examples thereof may include those described as examples ofthe hole-transporting compound used in the hole injection layerdescribed above. Examples thereof may include an arylamine derivative, afluorene derivative, a spiro derivative, a carbazole derivative, apyridine derivative, a pyrazine derivative, a pyrimidine derivative, atriazine derivative, a quinoline derivative, a phenanthrolinederivative, a phthalocyanine derivative, a porphyrin derivative, asilole derivative, an oligothiophene derivative, a condensed polycyclicaromatic derivative, and a metal complex. Examples thereof may alsoinclude a polyvinyl carbazole derivative, a polyarylamine derivative, apolyvinyl triphenylamine derivative, a polyfluorene derivative, apolyarylene derivative, a polyarylene ether sulfone derivativecontaining tetraphenyl benzidine, a polyarylene vinylene derivative, apolysiloxane derivative, a polythiophene derivative, and apoly(p-phenylene vinylene) derivative. These may be any of analternating copolymer, a random polymer, a block polymer, and a graftcopolymer, and may also be a polymer having a branched main chain andthree or more terminals, so-called a dendrimer.

[Light-Emitting Layer]

The light-emitting layer 3 c may be a light-emitting layer ofindependently emitting red light, green light, and blue light, or amixed light-emitting layer thereof. Alternatively, the light-emittinglayer may contain a compound having a hole-transporting property(hole-transporting compound) or a compound having anelectron-transporting property (electron-transporting compound). Anorganic EL material may be used as a dopant material, and thehole-transporting compound, the electron-transporting compound, or thelike may be appropriately used as a host material. The organic ELmaterial is not particularly limited, and a substance that emits lightat a desired emission wavelength and provides good light-emittingefficiency may be used.

As the organic EL material, any known material can be applied. Forexample, the material may be a fluorescent material or a phosphorescentmaterial. From the viewpoint of internal quantum efficiency, thephosphorescent material is preferably used. The light-emitting layer mayhave a single-layer structure or if desired, a multilayer structure madefrom a plurality of materials. For example, the fluorescent material isused for a blue light-emitting layer and the phosphorescent material isused for a green light-emitting layer and a red light-emitting layer.Various materials may be used in combination. Further, a diffusionprevention layer may also be provided between the light-emitting layers.

Examples of a fluorescent material exhibiting blue luminescence (bluefluorescent dye) may include naphthalene, perylene, pyrene, chrysene,anthracene, coumarin, p-bis(2-phenylethenyl)benzene, and derivativesthereof.

Examples of a fluorescent material exhibiting green luminescence (greenfluorescent dye) may include a quinacridone derivative, a coumarinderivative, and an aluminum complex such astris(8-hydroxy-quinoline)aluminum (Alq3).

Examples of a fluorescent material exhibiting yellow luminescence(yellow fluorescent dye) may include rubrene and a perimidonederivative.

Examples of a fluorescent material exhibiting red luminescence (redfluorescent dye) may include a4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran(DCM)-based compound, a benzopyran derivative, a rhodamine derivative, abenzothioxanthene derivative, and azabenzothioxanthene.

Examples of the phosphorescent material may include an organometalliccomplex containing metal selected from Groups 7 to 11 of thelong-periodic table (hereinafter, unless particularly otherwise noted,“the periodic table” is intended to refer to the long-periodic table).Preferable examples of metal selected from Groups 7 to 11 of theperiodic table may include ruthenium, rhodium, palladium, silver,rhenium, osmium, iridium, platinum, and gold. A ligand of the complex ispreferably a ligand in which a (hetero)) aryl group is coupled withpyridine, pyrazole, phenanthroline, or the like, such as a(hetero)arylpyridine ligand and a (hetero)arylpyrazole ligand, andparticularly preferably a phenylpyridine ligand or a phenylpyrazoleligand. Here, the (hetero)aryl represents an aryl group or a heteroarylgroup.

Specific examples of the phosphorescent material may includetris(2-phenylpyridine) iridium (so-called Ir(ppy)3),tris(2-phenylpyridine) ruthenium, tris(2-phenylpyridine) palladium,bis(2-phenylpyridine) platinum, tris(2-phenylpyridine) osmium,tris(2-phenylpyridine) rhenium, octaethyl platinum porphyrin, octaphenylplatinum porphyrin, octaethyl palladium porphyrin, and octaphenylpalladium porphyrin.

The light-emitting layer may contain a hole-transporting compound as itsconstituent material. Among hole-transporting compounds, examples of ahole-transporting compound having a low molecular weight may includevarious compounds described as the examples of the hole-transportingcompound in the hole injection layer 3 a described above, aromaticdiamines including two or more tertiary amines and two or more condensedaromatic rings substituted with nitrogen atoms, which is typified bydiphenyl naphthyl diamine (so-called α-NPD), an aromatic amine compoundhaving a starburst structure such as 4,4′,4″-tris(1-naphthylphenylamino)triphenylamine, an aromatic amine compound having a tetramerof triphenylamine, and a spiro compound such as2,2′,7,7′-tetrakis-(diphenylamino)-9,9′-spirobifluorene.

The light-emitting layer may contain an electron-transporting compoundas its constituent material. Among electron-transporting compounds,examples of an electron-transporting compound having a low molecularweight may include 2,5-bis(1-naphthyl)-1,3,4-oxadiazole (so-called BND),2,5-bis(6′-(2′,2″-bipyridyl))-1,1-dimethyl-3,4-diphenylsilole (so-calledPyPySPyPy), basophenanthroline (so-called BPhen),2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (so-called BCP,bathocuproin), 2-(4-biphenylyl)-5-(p-tert-butylphenyl)-1,3,4-oxadiazole(so-called tBu-PBD), and 4,4′-bis(9H-carbazol-9-yl)biphenyl (so-calledCBP).

[Electron Transport Layer]

The electron transport layer 3 d is provided for the purpose of furtherimproving the emission efficiency of the organic EL elements, and isformed from an electron-transporting compound capable of efficientlytransporting electrons injected from a cathode toward the light-emittinglayer between electrodes to which an electric field is applied.

As the electron-transporting compound used for the electron transportlayer, a compound that has high electron injection efficiency from thecathode or the electron injection layer 3 e and high electron mobilityand is capable of efficiently transporting injected electrons is usuallyused. Examples of a compound satisfying such conditions may include ametal complex of 10-hydroxybenzo[h]quinoline such as Alq3, an oxadiazolederivative, a distyryl biphenyl derivative, a silole derivative, a3-hydroxyflavone metal complex, a 5-hydroxyflavone metal complex, abenzoxazole metal complex, a benzothiazole metal complex,trisbenzimidazolylbenzene, a quinoxaline compound, a phenanthrolinederivative, 2-tert-butyl-9,10-N,N′-dicyanoanthraquinonediimine, n-typehydrogenated amorphous silicon carbide, n-type zinc sulfide, and n-typezinc selenide.

[Electron Injection Layer]

The electron injection layer 3 e fulfills a role of efficientlyinjecting electrons injected from the cathode into the electrontransport layer or the light-emitting layer. For the electron injectionlayer 3 e, an organic electron transport compound typified by anitrogen-containing heterocyclic compound such as bathophenanthrolineand a metal complex such as an aluminum complex of 8-hydroxyquinoline isused. When the electron injection layer 3 e of the organic electrontransport compound is doped with an electron-donating material, theelectron injection efficiency can be enhanced. As the electron-donatingmaterial, for example, an alkali metal such as sodium and cesium, analkali earth metal such as barium and calcium, a compound thereof (CsF,Cs₂CO₂, Li₂O, and LiF), or an alkali metal such as sodium, potassium,cesium, lithium, and rubidium is used.

As a procedure for forming each layer in the organic layer 3, a drycoating method such as a sputtering method and a vacuum depositionmethod and a wet coating method such as screen printing, a sprayingmethod, an inkjet method, a spin coating method, gravure printing, and aroll coater method are known. For example, a hole injection layer, ahole transport layer, and a light-emitting layer may be formed by a wetcoating method so that each film thickness is uniform, and an electrontransport layer and an electron injection layer may be each formed inturn by a dry coating method so that each film thickness is uniform.Further, all functional layers may be formed in turn by the wet coatingmethod so that each film thickness is uniform.

[Reflection Electrode]

In order to efficiently inject electrons, it is preferable that amaterial for the reflection electrode 4 as a cathode include a metalhaving a low work function. For example, an appropriate metal such astin, magnesium, indium, calcium, aluminum, and silver, or an alloythereof is used. Specific examples thereof may include an electrode madeof an alloy having a low work function, such as a magnesium-silveralloy, a magnesium-indium alloy, and an aluminum-lithium alloy. Thereflection electrode 4 may be formed as a single-layer film or amultilayer film on the organic layer 3 by a sputtering method or avacuum deposition method. The film thickness is not restricted as longas it can maintain the reflection action of the reflection electrode 4.

Next, the operation of the organic EL panel of the mirror device will bedescribed with reference to FIG. 4. When a driving voltage is applied tothe light-emitting layer 3 c in the organic layer through thelight-transmissive electrode 2 and the reflection electrode 4, lightgenerated in the light-emitting layer 3 c passes through thelight-transmissive electrode 2, is reflected on the reflection electrode4, and passes through the light-transmissive electrode 2. Thus, severaltens percent of the light is extracted from the front surface of thelight-transmissive substrate 1. Specifically, of light emitted from thelight-emitting layer 3 c, light L1 with an angle that is less than thecritical angle of each interface passes through the light-transmissiveelectrode 2 at a region including no metal mirror surface portion MIR,and proceeds toward the glass substrate 1. Other light L2 proceedingtoward the reflection electrode 4 is reflected on the reflectionelectrode 4, passes through the light-emitting layer 3 c, passes throughthe light-transmissive electrode 2, and proceeds toward the substrate 1.The light L1 and the light L2 are emitted toward a front space of thesubstrate 1 at the region including no metal mirror surface portion MIR.Remaining light L3 with an angle that exceeds the critical angle istotally reflected and proceeds toward the bank BK. Light L4 emitted froman edge face of the light-emitting layer 3 c and light L4 proceeding ina transverse direction also enter the bank BK, are repeatedly reflectedand attenuated, passes through the light-transmissive electrode 2,proceeds toward the substrate 1, and are partially emitted toward thefront space of the substrate 1. In contrast, when a part of light L5from the outside that enters from the space on the front surface side ofthe substrate 1 is reflected on the metal mirror portion MIR, and theother part thereof passes through the region including no mirror surfaceportion MIR, the light is reflected on the reflection electrode 4, andemitted outward.

Hereinafter, in modified examples of the first embodiment, a portiondifferent from that in the first embodiment will be mainly describedwith reference to FIGS. 5 to 10. Components represented by the samereference signs as in the first embodiment are the same as describedabove, and therefore the detailed description thereof will be omitted.

FIG. 5 shows a modified example of a mirror device that is the same asin the embodiment shown in FIG. 2 except that a metal bus line MBL isburied in a bank BK. In this case, the metal bus line MBL that iselectrically connected to a light-transmissive electrode 2 is formed oneach end edge of the light-transmissive electrode 2 buried in the bankBK so as to extend in a y direction. Therefore, power supply current canbe efficiently supplied to the light-transmissive electrode 2.

FIG. 6 shows a modified example of a mirror device that is the same asin the embodiment shown in FIG. 1 except that each of a plurality ofmetal mirror surface portions MIRs is rectangular, and the metal mirrorsurface portions MIRs and spaces SPs are each alternately disposed in afine check shape, that is, in a matrix, in an x direction and a ydirection on a xy main plane. In this case, uniform reflection andluminescent can be achieved as compared with metal mirror surfaceportions in stripes. Since banks BKs are formed from alight-transmissive dielectric material, for example, a transparent orscattering material, light can be further extracted from the banks BKsthrough a substrate 1.

FIG. 7 shows a modified example of a mirror device that is the same asin the embodiment shown in FIG. 1 except that portions opposite to banksBKs are configured so as to be covered with strip-shaped metal mirrorsurface portions SMIRs having the width of the banks BKs. In this case,the reflected light amount can be increased depending on the metalmirror surface portions in stripes.

FIG. 8 shows a modified example of a mirror device that is the same asin the embodiment shown in FIG. 6 except that a plurality of metalmirror surface portions MIRs are each separated, isolated, and disposedin a so-called dot shape. In this case, since the area of spaces SPs canbe made larger than the area of the metal mirror surface portions MIRs,the extraction efficiency of emitted light is improved.

FIG. 9 shows a modified example of a mirror device that is the same asin the embodiment shown in FIG. 8 except that a plurality of metalmirror surface portions MIRs are each separated, isolated, and disposed,and the shape of each of the metal mirror surface portions MIRs is acircle. As the shape of the metal mirror surface portions MIRs, variouskinds of shapes such as a rectangle, a polygon, a circle, and an ellipsecan be utilized. In this case, since the area of spaces SPs can bechanged and set relative to the area of the metal mirror surfaceportions MIRs, the degree of freedom that sets a ratio such as thereflection amount of light from the outside and the extractionefficiency of emitted light is improved.

In an example in which the metal mirror surface portions MIRs aredisposed in a dot shape, an aggregation having a shape in which apart ofeach dot is connected can be utilized.

FIG. 10 shows a modified example of a mirror device that is the same asin the embodiment shown in FIG. 9 except that a plurality of metalmirror surface portions MIRs are in such a mesh shape that the metalmirror surface portions MIRs each expand in x and y directions. In thiscase, since the area of spaces SPs is changed and determined relative tothe area of the metal mirror surface portions MIRs.

The mirror device having the above-described configuration can beutilized as an illuminated mirror such as a hand mirror and a vanitymirror, and can be utilized as an advertising board or a mirror with anilluminator attached to a pillar or a ceiling to make a space of a storelook wide.

Second Embodiment

Hereinafter, in a second embodiment, a portion different from that inthe first embodiment will be mainly described with reference to FIG. 11.Components represented by the same reference signs as in the firstembodiment are the same as described above, and therefore the detaileddescription thereof will be omitted.

As shown in FIG. 11, the second embodiment has a configuration that isthe same as in the first embodiment except that a light extractionstructure SBP is distributed and disposed on a front surface 1 a of asubstrate 1 except for a metal mirror surface portion MIR so as to covera light-emitting portion of an organic EL element OEL and have an areaexceeding the area of the light-emitting portion. In this case, theextraction efficiency of emitted light can be improved due to the lightextraction structure SBP. The light extraction structure SBP can beformed as a rough surface structure at a predetermined portion on thefront surface 1 a of the substrate 1, for example, by a water-blastingmethod or a fine sand-blasting method, or may be formed at apredetermined portion on the front surface 1 a of the substrate 1 byimprinting.

Light from the outside impinges on the metal mirror surface portion MIRand is reflected by the same. Light emitted from a light-emitting layerpasses through an organic layer and a light-transmissive electrode 2,and proceeds toward the glass light-transmissive substrate 1, light withan angle that is equal to or more than a critical angle is totallyreflected on an interface between the light-transmissive electrode 2 andthe light-transmissive substrate 1, and the remaining light enters theglass light-transmissive substrate 1. The light that enters thelight-transmissive substrate 1 enters the light extraction structure SBPat a region including no metal mirror surface portion MIR, and a part ofthe light is totally reflected due to randomness of the rough surfacestructure, and the remaining part is extracted into an air layer. Likethe light that is reflected on the interface between thelight-transmissive electrode 2 and the substrate 1, light that isreflected at a region including the metal mirror surface portion MIR isreflected on a reflection electrode 4, apart of the light is extractedfrom the rough surface structure into an air layer, and the remainingpart is reflected.

Third Embodiment

Hereinafter, in a third embodiment, a portion different from that in thefirst embodiment will be mainly described with reference to FIG. 12.Components represented by the same reference signs as in the firstembodiment are the same as described above, and therefore the detaileddescription thereof will be omitted.

As shown in FIG. 12, the third embodiment has the same configuration asin the second embodiment except that a protection film PFL is formed ona metal mirror surface portion MIR. In this case, the protection film.PFL protects the surface of the metal mirror surface portion MIR. Anoperation in the embodiment is the same as in the second embodimentexcept that light from the outside passes through the protection filmPFL and is reflected on the metal mirror surface portion MIR.

Fourth Embodiment

Hereinafter, in a fourth embodiment, a portion different from that inthe first embodiment will be mainly described with reference to FIG. 13.Components represented by the same reference signs as in the firstembodiment are the same as described above, and therefore the detaileddescription thereof will be omitted.

As shown in FIG. 13, the fourth embodiment has a configuration that isthe same as in the first embodiment except that a light extraction filmLEF is used as a light extraction structure so as to cover alight-emitting portion of an organic EL element OEL and have an areaexceeding the area of the light-emitting position, and is attached to afront surface 1 a of a substrate 1 and a metal mirror surface portionMIR, and a flattening layer FTL is provided only on the metal mirrorsurface portion MIR. In this case, the extraction efficiency of emittedlight can be improved due to the light extraction film LEF. A lightextraction structure SBP is a light extraction film LEF having aconcavo-convex structure of irregularities in several tens of nm to μmon one surface. The light extraction structure is formed by attachingthe other surface of the film. The shape of the concavo-convex structuremay be a shape capable of scattering light, and for example, thecross-sectional shape thereof may be a hemisphere, a trapezoid, or atriangle. The light extraction film. LEF is made of a transparent resinsuch as an acrylic resin, polyethylene, polypropylene, polyethyleneterephthalate, polymethyl methacrylate, polystyrene, polyether sulfone,polyarylate, a polycarbonate resin, polyurethane, polyacrylonitrile,polyvinyl acetal, polyamide, polyimide, a diallyl phthalate resin, acellulose resin, polyvinyl chloride, polyvinylidene chloride, andpolyvinyl acetate.

The light extraction film LEF is further attached to the metal mirrorsurface portion MIR, and gaps between the concavo and convex portion ofthe concavo-convex structure only on the metal mirror surface portionMIR are filled with a transparent flattening material having the samerefractive index as that of the light extraction film LEF. Thus, aregion of the light extraction film LEF having a random shape is buriedwith the transparent material having the same refractive index, toobtain the flattening layer FTL as a flat protection film. An operationin the embodiment is the same as in the second embodiment except thatlight from the outside passes through the flattening layer FTL and thelight extraction film LEF and impinges on the metal mirror surfaceportion MIR and is reflected by the same.

Fifth Embodiment

Hereinafter, in a fifth embodiment, a portion different from that in thefirst embodiment will be mainly described with reference to FIG. 14.Components represented by the same reference signs as in the firstembodiment are the same as described above, and therefore the detaileddescription thereof will be omitted.

As shown in FIG. 14, the fifth embodiment has a configuration that isthe same as in the second embodiment except that a light extractionstructure SBP such as a rough surface structure or a light extractionfilm is provided on the whole surface of a substrate, a flattening layerFTL is first formed at a predetermined position thereon, and a metalmirror surface portion MIR and a protection film PFL are layered only onthe flattening layer FTL, that is, a region of only the metal mirrorsurface portion MIR is replaced by a layered body of the lightextraction structure SBP, the flattening layer FTL, the metal mirrorsurface portion MIR, and the protection film PFL.

Light from the outside passes through the protection film PFL, andimpinges on the metal mirror surface portion MIR and is reflected by thesame. Light emitted from a light-emitting layer passes through anorganic layer and a light-transmissive electrode 2, and proceeds towarda glass light-transmissive substrate 1, light with an angle that isequal to or more than a critical angle is totally reflected on aninterface between the light-transmissive electrode 2 and thelight-transmissive substrate 1, and the remaining part of light entersthe glass light-transmissive substrate 1. The light that enters thelight-transmissive substrate 1 enters the light extraction structure SBPat a region including no metal mirror surface portion MIR, and a part ofthe light is totally reflected due to randomness of the rough surfacestructure, and the remaining part is extracted into an air layer. Likethe light that is reflected on the interface between thelight-transmissive electrode 2 and the substrate 1, light that isreflected at a region including the layered body of the light extractionstructure SBP, the flattening layer FTL, the metal mirror surfaceportion MIR, and the protection film PFL is reflected on a reflectionelectrode 4, a part of the light is extracted from the rough surfacestructure into the air layer, and the remaining part is reflected.Herein, the angle of emergence of light that is first emitted from thelight extraction structure SBP is different from the angle of incidenceof light that enters the light extraction structure SBP after thereflection on the metal mirror surface portion MIR. Therefore, the anglevaries randomly, and light that proceeds toward the region including nometal mirror surface portion MIR can proceed toward the air layer at acertain ratio.

Sixth Embodiment

Hereinafter, in a sixth embodiment, a portion different from that in thefirst embodiment will be mainly described with reference to FIG. 15.Components represented by the same reference signs as in the firstembodiment are the same as described above, and therefore the detaileddescription thereof will be omitted.

As shown in FIG. 15, the sixth embodiment has the same configuration asin the fourth embodiment except that a flattening layer FLT of thefourth embodiment shown in FIG. 13 does not exist. In this case, a lightextraction film LEF serves as a protection film of a metal mirrorsurface portion MIR.

Since light from the outside to the metal mirror surface portion MIR isnot directly reflected, and passes through the light extraction filmLEF, the mirror device is used as a decorative mirror just like frostedglass on a mirror or a reflection plate for bicycles. In particular,when the mirror device is used for a signboard in which a panel having atransmissive color character on the surface is disposed, or the like,the mirror device emits light even under no exposure to light at night,and can be distinguished, and light is reflected and diffusely reflectedon the metal mirror surface portion MIR and the light extraction filmLEF under exposure to light, to improve the visibility.

Seventh Embodiment

Hereinafter, in a seventh embodiment, a portion different from that inthe first embodiment will be mainly described with reference to FIG. 16.Components represented by the same reference signs as in the firstembodiment are the same as described above, and therefore the detaileddescription thereof will be omitted.

As shown in FIG. 16, the seventh embodiment has the same configurationas in the second embodiment except that a localized surface plasmonresonance structure LSPR is provided only on a metal mirror surfaceportion MIR. As the localized surface plasmon resonance structures LSPR,concavo-convex structure or irregularities with a wavelength size areformed on the surface of the metal mirror surface portion MIR. Whenlight emitted from a light-emitting layer enters a metal thin film,surface plasmons are generated. When a resonance condition of thesurface plasmons and the phase velocity of incident light coincide witheach other, the surface plasmons can be radiated outside (see JapanesePatent Application Laid-Open No. 2006-313667).

In the mirror device according to any of the embodiments describedabove, a sealing member that covers the light-emitting portion of eachof the plurality of organic EL elements formed on the back surface 1 bof the substrate 1 and seals the organic EL elements is provided, whichis not shown in the drawings. As the sealing member, a transparentdish-shaped sealing cap made of glass may be used. The transparentsealing cap is fixed around the light-emitting portion through anadhesive so as to cover the light-emitting portion. Thus, thelight-emitting portion is sealed and protected. The transparent sealingcap may be sealed by charging the inside thereof with an inert gas or aninert liquid. As the sealing member, a sealing film with gas barrierproperties made of a transparent resin such as poly(p-xylylene) andmultilayers of an inorganic film such as silicon oxide film and anorganic film may be used. As described above, it is preferable that thelight-emitting portion of the organic EL element be configured so as notto come into contact with moisture and oxygen in the air using thesealing member.

In the embodiments described above, as the light-transmissive substrate1, a plate of quartz glass or glass, a metal plate, a metal foil, aflexible resin substrate, a plastic film or sheet, or the like, can beused. In particular, a glass plate, and a transparent plate of syntheticresin such as polyester, polymethacrylate, polycarbonate, andpolysulfone are preferred. In a case of using a synthetic resinsubstrate, gas barrier properties should be noted.

In the embodiments described above, the organic layer is formed from alight-emitting layered body, but a light-emitting layered body may beconfigured by layering inorganic material films.

In the embodiments described above, examples in which a plurality oforganic EL elements R, G, and B are aligned is shown, but the presentinvention is not limited thereto. Even when a plurality of whitelight-emitting organic EL elements using a layered structure oflight-emitting layer such as a tandem structure including a plurality oflight-emitting layers or a mixed light-emitting layer are aligned foreach color, the same effect can be obtained.

In the embodiments described above, the metal mirror surface portionsMIRs are equally disposed. However, when the area of each of the metalmirror surface portions is much smaller than a light-emitting area ofthe organic EL elements, the metal mirror surface portions may berandomly disposed as long as the disposition of the metal mirror surfaceportions is visually checked as a uniform disposition.

REFERENCE SIGNS LIST

-   -   1 substrate    -   2 light-transmissive electrode    -   3 organic layer    -   3 a hole injection layer    -   3 b hole transport layer    -   3 c light-emitting layer    -   3 d electron transport layer    -   3 e electron injection layer    -   4 reflection electrode    -   BK bank    -   MBL bus line    -   MIR metal mirror surface portion    -   OEL organic EL element    -   SBP light extraction structure

1. A mirror device comprising: a light-transmissive substrate; and atleast one organic EL element supported on aback surface of thelight-transmissive substrate, the mirror device emitting light from afront surface of the light-transmissive substrate, wherein the organicEL element has an organic layer containing a light-emitting layerlayered between a light-transmissive electrode and a reflectionelectrode that are opposite to each other, the light-transmissiveelectrode is formed on the light-transmissive substrate, and the mirrordevice has a plurality of metal mirror surface portions that each havean area smaller than an area of the light-transmissive electrode and aredistributed and disposed on the front surface of the light-transmissivesubstrate so as to be opposite to the light-emitting layer.
 2. Themirror device according to claim 1, wherein the metal mirror surfaceportions are uniformly distributed.
 3. The mirror device according toclaim 2, wherein the metal mirror surface portions each have the sameshape and the same area.
 4. The mirror device according to claim 2,wherein the metal mirror surface portions each have a strip shape, andare aligned in stripes at constant intervals.
 5. The mirror deviceaccording to claim 2, wherein the metal mirror surface portions arealigned in a matrix at constant intervals.
 6. The mirror deviceaccording to claim 2, further comprising a light extraction structureprovided between the metal mirror surface portions.
 7. The mirror deviceaccording to claim 6, wherein the light extraction structure has a lightextraction film adhered to the metal mirror surface portions.
 8. Themirror device according to claim 6, wherein the light extractionstructure has a rough surface formed on the metal mirror surfaceportions.
 9. The mirror device according to claim 2, comprising aplurality of protrusions and a dielectric film that covers theprotrusions, the protrusions being formed on each of the metal mirrorsurface portions periodically at intervals that are equal to thewavelength of light emitted from the light-emitting layer.